DIY Video Projector Part II

For projector screens, how can we decide which options are the best and what quantitative methods do we have for measuring gain and viewing angles for different options?

So far I've seen 4 top contenders:

1. Da-Lite Screens
2. PLAS-TEX by Parkland Plastics
3. Blackout Cloth from fabric stores
4. Visiscreens??

this week we're starting our screen from blackout cloth. i post pics and performance numbers (possibly??) in a few days.
 
Just a thread?

I may be in the minority here, but does anyone else think that just starting nother thread for all of this info is a bad idea? The mountains of unorganized information from the last one will probably just continue if we dump all our new ideas and info into another thread. At the very least, this project deserves its own forum with separate threads. Ideally, a group of forums dedicated to each piece of the project would be used. diyprojectors.com is working on such a forum. I'm sure many others on here, including me, have access to forum creation and management and can start one if need be.

It just seems like an awfully good opportunity to add some organization to this very detail-oriented project at this time.

What do you guys think?
 
i agree completely

hokie,

i agree. we should use a new forum with better managed groups when one is available, or start several threads here temporarily that attempt some kind of organization while still being under the same topic. perhaps this will work:

DIY Projector - Screens
DIY Projector - LCD Panels
DIY Projector - OHP's
DIY Projector - Result Pics Only
DIY Projector - Custom Designs
DIY Projector - Optics

and etc...i think you get the point. what do you think? would this work or would it become cluttered without moderation?

also, i think we should contribute finished information to a website such as cowan's diyprojectors.com or some other place. ive tried to organize information at my own, but in the future hope to transfer it to a central site.

lets agree to do something, like the new threads, new forum, and/or site contribution and see this project continue to grow!
 
Re: i agree completely

SuperZoboo said:
hokie,

i agree. we should use a new forum with better managed groups when one is available, or start several threads here temporarily that attempt some kind of organization while still being under the same topic. perhaps this will work:

DIY Projector - Screens
DIY Projector - LCD Panels
DIY Projector - OHP's
DIY Projector - Result Pics Only
DIY Projector - Custom Designs
DIY Projector - Optics

and etc...i think you get the point. what do you think? would this work or would it become cluttered without moderation?

also, i think we should contribute finished information to a website such as cowan's diyprojectors.com or some other place. ive tried to organize information at my own, but in the future hope to transfer it to a central site.

lets agree to do something, like the new threads, new forum, and/or site contribution and see this project continue to grow!

hmm i may have had the idea of starting a new thread like this, but then i thought that cowans site would actually be great to continue with this information stream.... I really think it would be great. He already has the forum setup and he also has the sperate forums ready for the DIY projector specifics.
 

Jason

Powder Monkey
Paid Member
2000-10-08 1:19 pm
Melbourne
www.diyaudio.com
heck, id volunteer to mod if they need someone.
Moderators are being appointed as you type, although they will be "passive" - we don't want a police force just an easy way to keep things tidy and easy to use. Work has already started on cleaning out the completely useless stuff from the V1 thread.

SuperZ: There has been a notice across every forum for the past 4 days asking for moderator volunteers if you're interested.

At the very least, this project deserves its own forum with separate threads
Did you mean threads, or did you mean seperate forum areas? Did anyone notice the Video forum was created about 2 months ago? ;) Also that the recent site update allows you to view only video discussions?

If you decide on a forum structure then it will be created. Simple as that! I would even consider turning <a href="http://www.diyvideo.com">diyVideo.com</a> into a sister (brother? ;) site on its own if you think that would be a good idea.

Happy to create seperate forums per your suggestion below. Whatever you need, it's not a big deal and I'm happy to provide or create it.
 

Jason

Powder Monkey
Paid Member
2000-10-08 1:19 pm
Melbourne
www.diyaudio.com
<A href="http://www.diyaudio.com/wiki/index.php?page=VideoLinks">A complete list of the 760 links referenced in the DIY Video Projector thread</a> is now available in the Wiki.

If anyone would like to help name and categorize the links I'm sure everyone would really appreciate it! :) Editing the page is of course as easy as clicking the Edit link.
 
Beta 2

Well beta 2 is on the drawing board now, that means smaller box brighter bulb and higher resolution. Cooling for these things isnt going to be as big as a problem as I thought it would mine seems to run very cool with just a fan and vent. My friend at the electric supply is working on finding me a bulb, I told him 50,000 lumens 4500-6000K color temp about 10000 hour life and as small as can be so mabey he will have better luck.
 
hmm if Jason is willing to do all this, I'm willing to fully stay here. I just saw cowans site as being organized into diff sections, but if that can be done here to. I figure it started here, should stay here :) hehe

Oh, hehe I had sent Jason an email asking for moderator status a while back also. Mainly passively for the V1 thread. But if he ever needs some, I don't mind giving a hand also.
:)
 
Marklar, you punk! :) you do realize that we could all use a reflector like that. BTW, excellent job. Look what happens, I go on vacation, and you have to go and beat me to the final product. Oh well, I'll be finishing my box next weekend hopefully :) Good luck with your tweaking and perfecting. And thanks for all the great pictures of your progress. Makes me want to work more on the project! Seems like noone posts pictures except me and you Marklar :) .. hrmm.. come to think of it, theres not a lot of people making boxes like us, is there?
 

Jason

Powder Monkey
Paid Member
2000-10-08 1:19 pm
Melbourne
www.diyaudio.com
Thanks. As I said I don't think we need any kind of in-your-face moderation, just a way to keep an eye on the ball and get stuff done when it needs to get done. I've been working hardcore on my day-job for the past 12 months, and haven't made the time to give this place the attention it needs. Now that the new site revision is done it's a lot easier for me to roll with the punches, so to speak :)
 
Hi guys,
good to see you again on this new thread.
Let's continue our discussion.
Last night I made some test with fresnel panel.
As per woneill idea and from this link, which placed the fresnel panel in front of the LCD panel!
I put the fresnel 1,5" in front of the transparancy and I was surprised with the result, the projected image quality almost unchanged! there was slightly blurry at the image edge, but I think this was because my fresnel has a lot of scratched and slightly bended.
In this test, the fresnel panel doesn't act as objective lens, but as collimated lens.
If you already have 2 fresnel panel and LCD panel, you should try yourself and see the result.
The setup should go like this:
The light source should be placed at 1 fl of the first fresnel to produce parallel beam and will pass thru the LCD panel (placed right in front of it) and then hit the second fresnel panel (placed 1" to 2" in front of the LCD panel).
Light beam out from the second panel will collimate at 1 fl and at that point the objective lens should be placed.
This setup will answer one of the two LCD panel lighting conditions (another conditions is polarizing beam).

see you...
 
Hi Guys,

Good to see that the spirit lives on!

One possible downer about multiple other forums and web sites is that the previous thread acted as a single nexus for creative ideas from all over the world - some good, and some bad - but all were brought to scrutiny in one place, and while the thread was awkward to navigate, it was a single point of reference.

Anyway, back to business - there is actually a second reason I wanted to follow the LCD by a fresnel and concave lens - independent of collecting the maximum light through the LCD and maximising the contrast of it: I wanted to produce as parallel a beam as possible feeding into the main objective.

Why? To test my idea about anamorphic widescreen...

The theory is this - if you pass the beam through a concave cylindrical lens, and then subsequently pass the beam through a convex cylindrical lens of the same focal length, then in theory, the beam should be widened along one axis without disturbing the other one. With the two focal lengths of the lenses being equal, then I am hoping the overall focus of the beam will not be affected either.

Alternatively, using four cylindrical lenses (two PCV and two PCX) a configuration might be possible where the vertical axis gets compressed, while the horizontal axis gets expanded. This arrangement might be preferable because each axis gets "interfered with" less than with the single pair of lenses. Alternatively, each lens might introduce so much distortion that a less lenses is better. I honestly don't know.

I haven't tested this yet, and am waiting for my new lenses in the mail. But for this to work with the least possibility of distortion, I would guess that the more parallel the beam as it passes through this lens arrangement, the better... Hence another reason toplace a concave lens as close as is optimal to a fresnel after the panel.

I am only guessing about all this at the moment, and as I say, I have not tested it. What do you guys think?

Bill.

P.S. Gunawan, did you test the arrangement with the fresnel out on a laptop panel first to determine a rough optimal "viewpoint" for the image coming through the fresnel? This is probably very different from the optimal focal point of the objective lens. Having the actual viewpoint of the fresnel too close, or too far away can result in significant corner distortion.
 
blahn
Marklar,

Have you thought of using an adjustable 90 deg projection lens ,like overhead projectors, with your setup? so you could lean the box upright against a wall, out of way, and still be able to adjustment the image placement?

That would be what Im gonna do with beta 2, I really want to find like an old grandfather clock or something like that and cram all the stuff in there so it sits at the back of the room and looks like a peice of furniture.

HokieTT
Can you please tell me how you created a hole in your reflector big enough for the bulb base to pass through?

Also, do you have any more details for us concerning how to get a reflector like yours? I got a reflector in, but I think it might be too shallow to make efficient use of the light. Thanks.

I used an air die grinder to make the hole bigger as for making it the right size i had to find the focal point so i stick my finger in the hole umm hehe anyway i put it in there and looked stright at the reflector until the reflector turned flesh color then I measured the bulb and marked a hole then cut it.
Here is what I got the reflector off of.
Cooper Lighting
 
still going...

for anyone with the fuji vp5110b projection lens, i bought one from edmund for six bucks. as is, it's practically useless, but if you take it apart, there's some pretty decent lenses inside. i think this is the same one that surplus shed is selling for more money. it's got 2 pcx 1pcv and 1 dcx. i haven't made any precise measurements on them yet, but i am able to project a clear image with the convex lenses. i may try using the pcv in my light stage(before the image)